Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications

abstract: Semiconductor nanowires (NWs) are one dimensional materials and have size quantization effect when the diameter is sufficiently small. They can serve as optical wave guides along the length direction and contain optically active gain at the same time. Due to these unique properties, NWs ar...

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Other Authors: Sun, Minghua (Author)
Format: Doctoral Thesis
Language:English
Published: 2011
Subjects:
PL
TEM
Online Access:http://hdl.handle.net/2286/R.I.9522
id ndltd-asu.edu-item-9522
record_format oai_dc
spelling ndltd-asu.edu-item-95222018-06-22T03:02:11Z Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications abstract: Semiconductor nanowires (NWs) are one dimensional materials and have size quantization effect when the diameter is sufficiently small. They can serve as optical wave guides along the length direction and contain optically active gain at the same time. Due to these unique properties, NWs are now very promising and extensively studied for nanoscale optoelectronic applications. A systematic and comprehensive optical and microstructural study of several important infrared semiconductor NWs is presented in this thesis, which includes InAs, PbS, InGaAs, erbium chloride silicate and erbium silicate. Micro-photoluminescence (PL) and transmission electron microscope (TEM) were utilized in conjunction to characterize the optical and microstructure of these wires. The focus of this thesis is on optical study of semiconductor NWs in the mid-infrared wavelengths. First, differently structured InAs NWs grown using various methods were characterized and compared. Three main PL peaks which are below, near and above InAs bandgap, respectively, were observed. The octadecylthiol self-assembled monolayer was employed to passivate the surface of InAs NWs to eliminate or reduce the effects of the surface states. The band-edge emission from wurtzite-structured NWs was completely recovered after passivatoin. The passivated NWs showed very good stability in air and under heat. In the second part, mid-infrared optical study was conducted on PbS wires of subwavelength diameter and lasing was demonstrated under optical pumping. The PbS wires were grown on Si substrate using chemical vapor deposition and have a rock-salt cubic structure. Single-mode lasing at the wavelength of ~3000-4000 nm was obtained from single as-grown PbS wire up to the temperature of 115 K. PL characterization was also utilized to demonstrate the highest crystallinity of the vertical arrays of InP and InGaAs/InP composition-graded heterostructure NWs made by a top-down fabrication method. TEM-related measurements were performed to study the crystal structures and elemental compositions of the Er-compound core-shell NWs. The core-shell NWs consist of an orthorhombic-structured erbium chloride silicate shell and a cubic-structured silicon core. These NWs provide unique Si-compatible materials with emission at 1530 nm for optical communications and solid state lasers. Dissertation/Thesis Sun, Minghua (Author) Ning, Cun-Zheng (Advisor) Yu, Hongbin (Committee member) Carpenter, Ray W. (Committee member) Johnson, Shane (Committee member) Arizona State University (Publisher) Engineering characterization Infrared Nanowire PL TEM eng 157 pages Ph.D. Electrical Engineering 2011 Doctoral Dissertation http://hdl.handle.net/2286/R.I.9522 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2011
collection NDLTD
language English
format Doctoral Thesis
sources NDLTD
topic Engineering
characterization
Infrared
Nanowire
PL
TEM
spellingShingle Engineering
characterization
Infrared
Nanowire
PL
TEM
Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
description abstract: Semiconductor nanowires (NWs) are one dimensional materials and have size quantization effect when the diameter is sufficiently small. They can serve as optical wave guides along the length direction and contain optically active gain at the same time. Due to these unique properties, NWs are now very promising and extensively studied for nanoscale optoelectronic applications. A systematic and comprehensive optical and microstructural study of several important infrared semiconductor NWs is presented in this thesis, which includes InAs, PbS, InGaAs, erbium chloride silicate and erbium silicate. Micro-photoluminescence (PL) and transmission electron microscope (TEM) were utilized in conjunction to characterize the optical and microstructure of these wires. The focus of this thesis is on optical study of semiconductor NWs in the mid-infrared wavelengths. First, differently structured InAs NWs grown using various methods were characterized and compared. Three main PL peaks which are below, near and above InAs bandgap, respectively, were observed. The octadecylthiol self-assembled monolayer was employed to passivate the surface of InAs NWs to eliminate or reduce the effects of the surface states. The band-edge emission from wurtzite-structured NWs was completely recovered after passivatoin. The passivated NWs showed very good stability in air and under heat. In the second part, mid-infrared optical study was conducted on PbS wires of subwavelength diameter and lasing was demonstrated under optical pumping. The PbS wires were grown on Si substrate using chemical vapor deposition and have a rock-salt cubic structure. Single-mode lasing at the wavelength of ~3000-4000 nm was obtained from single as-grown PbS wire up to the temperature of 115 K. PL characterization was also utilized to demonstrate the highest crystallinity of the vertical arrays of InP and InGaAs/InP composition-graded heterostructure NWs made by a top-down fabrication method. TEM-related measurements were performed to study the crystal structures and elemental compositions of the Er-compound core-shell NWs. The core-shell NWs consist of an orthorhombic-structured erbium chloride silicate shell and a cubic-structured silicon core. These NWs provide unique Si-compatible materials with emission at 1530 nm for optical communications and solid state lasers. === Dissertation/Thesis === Ph.D. Electrical Engineering 2011
author2 Sun, Minghua (Author)
author_facet Sun, Minghua (Author)
title Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
title_short Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
title_full Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
title_fullStr Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
title_full_unstemmed Optical and Crystal Structure Characterizations of Nanowires for Infrared Applications
title_sort optical and crystal structure characterizations of nanowires for infrared applications
publishDate 2011
url http://hdl.handle.net/2286/R.I.9522
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